df.valueCounts()

Input DataFrame: rowsCount = 7, columnsCount = 5

name		age	city	weight	isHappy
firstName	lastName
Alice	Cooper	15	London	54	true
Bob	Dylan	45	Dubai	87	true
Charlie	Daniels	20	Moscow	null	false
Charlie	Chaplin	40	Milan	null	true
Bob	Marley	30	Tokyo	68	true
Alice	Wolf	20	null	55	false
Charlie	Byrd	30	Moscow	90	true

Output DataFrame: rowsCount = 5, columnsCount = 2

city	count
Moscow	2
London	1
Dubai	1
Milan	1
Tokyo	1

df.valueCounts { name and city }

Input DataFrame: rowsCount = 7, columnsCount = 5

name		age	city	weight	isHappy
firstName	lastName
Alice	Cooper	15	London	54	true
Bob	Dylan	45	Dubai	87	true
Charlie	Daniels	20	Moscow	null	false
Charlie	Chaplin	40	Milan	null	true
Bob	Marley	30	Tokyo	68	true
Alice	Wolf	20	null	55	false
Charlie	Byrd	30	Moscow	90	true

Output DataFrame: rowsCount = 6, columnsCount = 3

name		city	count
firstName	lastName
Alice	Cooper	London	1
Bob	Dylan	Dubai	1
Charlie	Daniels	Moscow	1
Charlie	Chaplin	Milan	1
Bob	Marley	Tokyo	1
Charlie	Byrd	Moscow	1